Timo Glock was taken to hospital after his crash on Suzuka's final corner
Toyota's Timo Glock will miss the Brazil Grand Prix after suffering a cracked vertebra during qualifying for the race in Japan.
The 27-year-old German did not compete in Suzuka, but it was thought his injuries were limited to a leg wound.
However, tests revealed he also suffered a back injury in a high-speed crash in the second qualifying session.
Japanese reserve driver Kamui Kobayashi will make his F1 debut as Glock's replacement in Sunday's race.
The 23-year-old stood in for Glock during Friday practice for the Japanese Grand Prix, as the German was suffering from a heavy cold.
Glock was back in the car for qualifying the following day, but he lost control at the final corner of the Suzuka circuit and hit a tyre wall.
He was stretchered into an ambulance and had stitches in a a five-centimetre cut in his left leg.
"Based on the initial diagnosis, we fully expected Timo to return in Brazil," said Toyota president John Howett.
"But unfortunately a different injury has been revealed which prevents that.
"He will remain in Germany to recover and we hope he can recuperate in time for Abu Dhabi, although at this stage the situation is not clear."
Kobayashi competes in the GP2 Series, and joined Toyota as their test driver in 2007.
He will be the fourth youngest driver on the grid at Interlagos, behind Sebastien Buemi, Jaime Alguersuari and Sebastian Vettel.
Timo Glock interview after Suzuka crash